1. Her foot's not going the right way. I can't find a ref pic, but if you stand like that yourself, you'll see the right foot would be pointing forward.
2. Her hair and skirt are being blown in two different directions.
3. If the brown part at the bottom is supposed to be the floor, it doesn't have much depth to show that.
4. Her left foot is too oval shaped. The way you've drawn it makes it look like she's actually standing on the tips of her toes when really shes standing on the pads of her toes, ya'know? Pic related for reference of how they should really look. Change to fit the type of shoes she's wearing obviously
5. Her hair is also a lot brighter where the light is shining than her skirt. The books in the background show that the amount of light is consistent from top to bottom, so the light on her skirt should be brighter.
I hope this wasn't to nitpicky, this drawing is really cute anon!